Meta

Earlier, I had written an article in this blog titled, “Sophisticated Time-Awareness – The Human Spark?” A summary of the article can be found here. In a nutshell, the article hypothesises that sophisticated time-awareness (STA) can explain most of the unique cognitive traits that makes us human. I deliberately formatted it as a scientific article to highlight the use of rigorous logic and reason in expounding the hypothesis, lest it is belittled by those with an exacting scientific bent. The downside is that, for non-technical folks, the article became difficult to read and comprehend, and hence boring. Therefore, I decided to write a non-technical version of the same article as a narrative, a story, in the hope that many of us will find this version enjoyable to read and easy to understand. Let us start…

“What is it that makes us human?”, “In what ways are we different from animals?” – I am sure almost all of us have asked these or similar questions, and have some kind of answers to them. Just for fun, also google this or ask around. Chances are that, most of the time, the answers will be among the following traits or qualities:- opposable thumbs, big brains, big great toe, erect posture, self-awareness, ability to think, logic, reason, intelligence, ability to learn, long childhood, use of symbols, sophisticated tool-making, language, use of fire, foresight, mental time travel, mind-reading, memory, spirituality, religiousness, rituals, humour, music, art, ability to appreciate beauty, culture, morality, compassion, altruism, ability to laugh and cry, clothing, cooking, blushing, kissing, eroticism. Phew! The interesting thing is that all these answers are (mostly) correct! And the list is not even complete!

Please note: this article, although non-technical, assumes that the reader subscribes to the scientific fact that we are a biological life form, having evolved from lower animals. Specifically, we are Homo sapiens, a species of bipedal apes belonging to the genus Homo and sub-tribe Hominina (hominids or hominins). May be we are on our way to being something ‘better’ than just animals, but that is not the subject of this article. Also, this article does not subscribe to notions described in some religious scriptures, for example, that we were created in the image of a supernatural god, who made us out of clay and breathed life into us, or the like. Thus non-technical does not mean non-scientific.

A little snippet to arouse your curiosity: Archaeological evidence clearly shows that, during the course of human evolution, all the anatomical features that make us Homo sapiens appeared about 200,000 years ago. The appearance of these features can be fairly well explained by evolution by natural selection. But the most puzzling finding from archaeological excavations pertaining to human evolution is this: almost all of the unique human traits, such as the ones listed in paragraph 2, appeared almost suddenly only about 40,000 to 50,000 years ago. Before 50,000 years, evidence shows that we, though anatomically Homo sapiens, were behaving just like any other ape species; but excavations dating back to within 40,000 years shows clear evidence of ritualistic burial of the dead, cave art, body ornaments, sophisticated tool-making, specialised hunting techniques, barter and trade over a distance, implying fairly sudden (in geological time scale, that is) appearance of multitude of unique human qualities. In other words, anatomically modern humans appeared about 150,000 years before the appearance of behaviourally modern humans! What was going on for those 150,000 years? Nobody really knows. Further, how can so many unique traits appear simultaneously and fairly suddenly? Any theory trying to explain human evolution must address these 2 important questions.

Before we move on further, we need to understand a few concepts about components of human nature, namely cognition, emotion and behaviour. These aspects of human nature are intimately linked, and their inter-relationship is subject of fascinating research. The terms emotion and behaviour are easy to understand, but what do we understand by the term cognition?

Simply put, cognition is the process of thought; it refers to our perceptions, beliefs, mental attitudes, biases, imagination and knowledge; it includes the way we think about things – what we say about something or someone to ourselves. It is the central processor, which receives input from our sense organs, and modulates both our emotions and behaviour. It is our cognition which gives us the unique ability to think rationally, to make moral judgements, to appreciate beauty, to form complex societies and nations, and, to wonder who we really are and what our place in this Universe is.

Please note that the long list of human traits mentioned in paragraph 2 includes cognitive, emotional and behavioural traits. More importantly, please note that the article, “Sophisticated Time-Awareness – The Human Spark?” discusses only cognitive traits, because they are more important in defining who we are, and cognitive traits can in turn easily explain emotional and behavioural traits. Hence, this non-technical version is also going to focus mainly on cognitive traits and explain the hypothesis that STA is the cognitive trait that makes us human. One more caveat: let us relax our rules and use the terms cognition and thought interchangeably.

So, how did we become thinking beings?

2. Evolutionary Background

Let us take a detour and look at a sketchy outline of evolution of hominids. Hominids are the taxonomical group to which human beings belong; at present we, Homo sapiens, are the only surviving species of the group. The first hominids appeared about 2.5 million years ago. They were followed by many intermediate species for the next 1.8 million years.

Figure 1. Left: A tentative evolutionary tree of the sub-tribe Hominina. Right: The temporal span of key anatomical and behavioral traits and of major Paleolithic culture-stratigraphic units in Africa and western Eurasia (Reproduced with permission from Klein).

About 600,000 years ago, the hominids branched into two groups from a common ancestor in Africa. One group gave rise to the Neanderthals (Homo neanderthalensis) who migrated out of Africa and settled in various continents including Europe. The other group stayed in Africa (around the Great Lakes of eastern Africa) and it was out of this group Homosapiens are believed to have evolved about 200,000 years ago. The Neanderthals are known to have existed in Europe for at least 40,000 years until they became extinct about 28,000 years ago. A very interesting aspect of evolutionary anthropology is that till Neanderthals became extinct they did not show any evidence of significant development of intelligence or cognition.

As mentioned in the Section 1, the early human beings who first appeared in Africa around 200,000 years ago are called anatomically modern humans and they too do not show any evidence of significant advances in cognition. Such advances appeared suddenly about 40-50,000 years ago and mark the appearance of behaviourally modern humans. This has been aptly called ‘The Great Leap Forward’. As you can make out, this fairly sudden transition to behaviourally modern humans happened about 150,000 years after the appearance of first anatomically modern humans. Such behaviour implies appearance of unique human cognitive traits (remember the triad of cognition, emotion and behaviour?). The question that comes to our mind is this: Why did sophisticated cognition and intelligence develop in only one species of hominids i.e. Homo sapiens in Africa, and not in others?

Some of you might think that it is our brain size which created the perfect soil for cognition to sow its seeds. But do you know that the hominids’ brain had nearly reached that of modern human about 600,000 years ago? Moreover, the Neanderthal’s brain was as large as, if not larger than, human brain. So brain size alone cannot account for the sudden appearance of human cognition about 50,000 years ago. The reason why brains started enlarging in early hominids is a fascinating story in itself but we will not go into that. Suffice it to say that a large brain had been present in hominids which did not display sufficient degree of cognitive sophistication. Thus, large brain alone cannot account for modern human behaviour.

It is now time to introduce the concept of cognitive modules. Evolutionary psychologists believe that cognition evolved as a series of functional mental modules in response to environmental stimuli to which early hominids were frequently exposed. Natural selection favoured those modules which were successful in aiding the survival and reproduction of early hominids. For example, there may be dedicated mental modules for tool making, language, self-awareness etc. It is important to realise that there is compelling evidence to believe that these modules did exist in some early hominids, especially Neanderthals, albeit in a primitive form. Therefore, we can come to the conclusion that individual cognitive modules did not appear suddenly in humans but rather have been evolving over hundreds of thousands of years in early hominids.

But, the evolution of individual cognitive modules cannot explain the simultaneous appearance of myriad facets of modern human behaviour. Think about this: Each one of this behaviour like cave art, ritualistic burial, body ornament etc is so unique and so unprecedented, and has never been seen in any other life form before. The chances of multiple and diverse, but unique and unprecedented behavioural traits, all appearing independently, or, all becoming sophisticated in a single species almost at the same time, is almost nil. So how else could modern human behaviour have appeared suddenly about 50,000 years ago?

I think the above conundrum can be explained by the appearance or sophistication of a more fundamental cognitive module in Homo sapiens. This module must be the spark which lighted up all the other pre-existing modules; it must be the catalyst which augmented their function. The appearance of a single module is more probable than the independent but simultaneous sophistication of multiple cognitive modules. Because of the fundamental (so called ‘domain non-specific’) nature of such a module, one can assume that it can simultaneously affect the function of various pre-existing cognitive modules and bring about augmentation of their functions.

3. Sophisticated Time-Awareness – What is it?

If this is the case, what is that fundamental cognitive module? It is tempting to presume that it is self-awareness. After all, human cognition is mostly about making sense of oneself in relation to the environment. But in my opinion, that is not the case. I think the fundamental cognitive module which is responsible for the appearance of modern human behaviour about 50,000 years ago is the module which made us aware of time (and space). The resulting sophisticated time-awareness (STA) can explain many uniquely human cognitive and behavioural traits such as multi-part tool-making, logic, language, notion of causation, episodic memory, mental time-travel, existence-awareness, religion, music, arts and humour.

Sophisticated time-awareness is the “conscious” awareness that time exist, that there is an arrow of time, that there is a past, present and a future. One Mr Pöppel has listed the following ‘elementary time experiences’: (i) duration; (ii) non-simultaneity; (iii) order; (iv) past and present; and (v) change, including the passage of time.

Only with reference to time can you develop a flow of thought, which otherwise will be jumbled nonsense. This fundamental and innate awareness of time is the foundation upon which all human cognition is built. Without the ever-present denominator of awareness of time, our thoughts and imaginations will not ‘make sense’ – probably that is what happens in animals; it is conceivable that animals (especially our evolutionary neighbours such as the chimpanzees) may have units of thought (whatever that unit turns out to be), but because they are not referenced to time, they make no useful sense to the animals.

In the same vein, it is possible to theorise the evolution of awareness of a three dimensional space. Even though many creatures are more adept than us in navigating through space, awareness of three dimensions of space, and hence the ability to manipulate objects and symbols spatially in one’s mind as well as to ‘travel’ anywhere in space in one’s imagination are unique human characteristics.

At this juncture, we have to go off a tangent. Long ago, I had read the classic philosophical treatise, Critique of Pure Reason, by the great philosopher, Immanuel Kant (abridged version, not the original, for the original is a difficult read). Without going into the details of what Kant said, let me just tell you that he made important contributions to the thorny issue of how we perceive reality. Before Kant, philosophers such as Hume, proposed that all our awareness was the result of external sensory data. This lead to a logical problem called reductio ad absurdum, which basically means that if you pursue Hume’s theory to its logical conclusion you end up with nothingness! Kant rectified the problem by proposing that though all awareness comes from sensory data, it is not due to sensory data – which means that there is a priori knowledge residing in our brains which is independent of sensory data; this a priori knowledge sorts out the incoming data so that it makes sense to us. Kant had also mentioned that the fundamental a priori knowledge is those of time and space! For a moment I thought that my ideas about human awareness of space and time are identical to the a priori knowledge of space and time that Kant was talking about. It then dawned on me that they are qualitatively different.

Kantian a priori knowledge of space and time is not unique to humans but is present in any lower life form which has a sophisticated apparatus of sensory perception. For example, it has been clearly shown in experiments that rats can be conditioned to respond differently to different intervals of time according to expectations of pleasure and pain. But conscious awareness that time exists is a unique human quality; lower animals may have the ability to sort out sensory data according to time, but it is doubtful whether they are aware of the existence of time.

4. Role of STA in Modern Human Behaviour

Now that we have an idea what I mean by STA, let us see how it can explain the appearance of many modern human traits, especially multi-part tool-making, existence-awareness, logic and reason, language, notion of causation, episodic memory, mental time travel, foresight, free will, religion, faith, rituals, music, intentional stance, “theory of mind”, arts and humour.

4.1. Multi-Part Tool-Making

The ability to create and use tools is present in many animals. For example, it is well known that chimpanzees can fashion a tool from a twig or a branch to probe termite nests. But none of the animals can match the level of sophistication of humans. Modern airplanes, rockets, computers, nano-robots, and artificial satellites are all examples of the unprecedented ingenuity of humans as tool-makers.

Let us consider one of the earliest tools made by humans – throwing spear. It first appears in Africa as a tool 80,000 to 100,000 years ago; it is so sophisticated a tool when compared to others made by early hominids, that it, among other things, is considered to be one of the most definitive sign of arrival of modern humans. The early hominids did show some propensity towards tool-making. The most common tool made by them is the stone hand-axe, used for hunting and cutting carcass. You tend to get the impression that making of a hand-axe too represents a sophisticated tool-making ability. But it is not. If you really think about it, the planning part of making a hand-axe is not anymore sophisticated than some of the tools used by lower animals – it is a two step process, at the most, which only gets repeated over and over. No wonder, then, that the stone hand-axe has been used by hominids for nearly 1.6 million years, with no significant improvement in its design or sophistication. But making of a throwing spear by the earliest humans is a completely different kettle of fish. Why? Because it is a composite, multi-part tool. Let us list the steps involved in the making of it:

1. Make a small axe from stone (like the hand-axe, but smaller)
2. Fashion a long stick from the branch of a tree
3. Make a small slit at one end of the stick
4. Keep some kind of tie made of natural fibre handy
5. Place the axe in the slit
6. Tie it firmly with the fibre.

Note that each step is followed by an implicit ‘then’; in fact, it is so implicit to us that we take its existence for granted without even realising what a unique human ability it is! When we think and plan we are sequencing the steps all the time! The intuitive awareness which we have that step 2 follows step 1 and so on is not at all obvious to animals – they can probably execute 2 steps in correct sequence, or 3 steps at the most. It is intriguing to note that the possible permutations for a 2 step process is only 2 (2!), whereas the number of permutations possible for a 3 step process is 6 (3!) and for a 6 step process is 720 (6!). It is therefore possible that animals are able to execute 2 step process purely because of chance – since there are only 2 ways of doing it, the chances are high (50%) that they will successfully accomplish it in the first attempt, so much so it gives you an illusion of planning and foresight. When the number of possible steps increases, the number of possible permutations increases explosively (combinatorial explosion), and it becomes less probabilistic for the animal to execute the correct sequence by trial and error alone, especially when it is not equipped to know that a particular combination has already been tried before. The fact that humans possess a uniquely elaborate working memory may thus be directly related to STA. You will also notice that we humans can improve upon the above sequence by pushing Step 4 to Step 2 etc. The ability to rearrange and refine mental rules of this type, and probably the ability to learn in general, is due to STA.

4.2. Existence-Awareness

It is upon the brilliant foundation of cognitive awareness of time that the second important cognitive module is built – awareness of existence. In other words, cognitive awareness of time is the reason for cognitive awareness of existence. It is usually mistaken for awareness of self only (self-awareness). It is important to realise that awareness of existence also implies simultaneous awareness of existence of your fellow humans, other living beings, non-living things – everything in the universe or nature that you can possibly be aware of (so called, other-awareness). Awareness of self only occurs in relation to awareness of your surroundings – you, the subject, are aware of your existence only with respect to the objects that exist.

It is interesting to note that the above concept is in complete concurrence with that of Robert M. Pirsig, author of Zen and the Art of Motocycle Maintenance. In that brilliant book, he defines a concept called Quality. According to him, Quality is a fundamentally important event – the event where the subject becomes aware of the object; it is Quality which gives rise to awareness of subject and object; it is the fountainhead of all awareness and consciousness in humans. I realise now that he was actually referring to the point of interface between cognitive module of awareness and Quality reality, the event which gives rise to perception of reality, to be precise!

Coming back to awareness of existence, it is easy to understand that the importance of the sense of self-existence as a cognitive tool, if cognition itself has to bestow survival advantage to the organism – there is no way you can adopt cognitive methods (like reasoning, thinking, imagining, planning etc) to ensure your survival if you are not cognitively aware of yourself, and your self-interests.

4.3. Logic and Reason

There is more; Logic, the mother of reason, could not have developed beyond a primitive level if it was not anchored by the denominator of time. There are two common modes of logical reasoning, namely inductive and deductive reasoning. Inductive reasoning means making generalisations based on specific events; deductive reasoning means making specific conclusions based on generalisations. Such reasoning cannot be accomplished without sequential mental rules and linear thinking, which in turn is possible only because of STA.

So too is the concept of numbers, upon which all of mathematics, the queen of all intellectual endeavours, is built. The earliest known archaeological evidence of numbers is tally marks found on a piece of Baboon fibula excavated from Lebombo Mountains in Swaziland dating back to approximately 44,000 years ago. This date is consistent with the hypothesis that modern human behaviour appeared approximately 40,000 to 50,000 years ago. Although numbers were assigned sophisticated symbols (due to sophisticated space-awareness) only much later, the concept of ordinality (for example, that 2 is greater than 1) is based upon the awareness that 2 ‘comes after’ 1! The concept that number 1 comes before number 2, and so on, is so taken for granted that it is easy to miss the fact that we are using the concept of time to make sense of numbers and to manipulate them. In other words, the concept of numbers is a form of cross-modal abstraction of STA. ‘Cross-modal abstraction’ is a fancy term for a mental process, where one mental concept (in this case, time) is applied to make sense of another completely different mental concept (in this case, ordinality).

This idea can be generalised further to hypothesise that mathematical theorems, proofs, formulae, equations, and algorithms are all embedded with a sophisticated concept of time. In essence, all human endeavours based on logic and reason, such as philosophy, mathematics, science and technology, are built upon STA.

4.4. Language

Consider language. Did you know that the tool making and language centres, which are among the earliest motor modules to evolve uniquely in humans are in close proximity in the human brain, namely in the Broca’s area?! In common with multi-part tool-making ability, language involves making unique sounds in precise sequence for it to make sense. Primitive animals, including the Neanderthals, did communicate using vocalised sounds, but it appears that such sounds used to denote a particular object or event must have involved only two syllables at the most. Complex sounds involving more than two syllables require that the syllables need be in precise sequence to form a word that can consistently denote the same object or event. And such sequencing is possible only with time-awareness.

4.5. Notion of Causation or Teleology

Notion of causation or the much fancier term, teleology, is a unique human cognitive trait that attempts to explain phenomena in terms of cause and effect. This notion of causation is one of the earliest cognitive traits to appear during the course of human life; children as young as three years old can assign causes and effects to events. It is not unreasonable to presume that teleology could have developed early in the evolution of modern human behaviour 40 – 50,000 years ago.

Teleology gives humans a unique insight into cause and effect, and the ability to manipulate causes to achieve desired results. Moreover, the notion of causation is a central principle in the scientific method. It also gives rise to the philosophical doctrine that everything that exists must have a cause or a purpose. Misapplication of this doctrine may be what causes humans to believe in astrology, superstition, intelligent design, or a supernatural creator.

Cause precedes effect and effect follows cause. Thus the notion of causation would be impossible without STA. It is possible that some primitive notion of causation existed in earlier hominids prior to 200,000 years ago, as evidenced by their ability to create primitive tools, such as stone hand-axes, and by their likely mastery of fire. I would argue that the human notion of causation differs from such primitive concepts in its ability to assign causes and events to more than two events. In other words, humans are able to sequence many events to form a chain of causation, e.g., “A is the cause of B, which in turn is the cause of C.”. The similarity of such a mental rule to those of multi-part tool-making, logical thought and language is striking. It is clear that such sophistication in the notion of causation is possible only because of STA.

4.6. Episodic Memory

Two main types of long-term human memories have been described. Procedural or non-declarative memory refers to unconscious memories, such as skills (e.g., learning to swim). Declarative memory refers to memories that can be consciously recalled, such as facts and events. Declarative memory contains two sub-types, semantic and episodic memories. Semantic memory stores general factual knowledge about the world that is independent of personal experience, such as the fact that bananas are yellow. Importantly, procedural memory and semantic memory are not unique to humans.

Episodic memory, on the other hand, is the memory of specific events and can be thought of as a catalogue of memories of events together with their spatio-temporal relationships, which are stored in a more or less correct sequence. This type of memory is unique to humans. The distinguishing feature of episodic memory is the assignment of time and space to events before they are stored. The uniqueness of episodic memory in humans can thus be explained by the uniquely human trait of STA.

4.7. Mental time-travel, Foresight and Free Will

Some people might ask, “If we have intuitive awareness of flow of time, how is it then possible that we can jump in our imaginations from past to present or possible future at will?” They have wrongly presumed that the awareness of unidirectional flow of time that characterises the reality we perceive can produce only unidirectional imaginations time-wise (ie., imaginations flowing in only one direction with respect to time, from past to future). It is precisely because of this intuitive awareness of past, present and future that we are able to jump to different time zones in our imagination at will, that we are able to change the denominator of time in our thoughts at will, all the while aware that the denominator has changed, because we instinctively know whether a particular thought pertains to the past, present or future. In fact, this innate ability to change the denominator of time in our thoughts and imaginations is absolutely essential if we want to reflect upon the possible future consequences of our proposed actions (foresight)! After evaluating all possible future consequences, we choose to perform a particular action (free will). Thus the unique human traits of foresight and free will are impossible without STA.

4.8. Religion / Faith / Ritual

The appearance of STA and sophisticated existence-awareness is a unique event in the history of evolution. Though they provide humans with unique cognitive gifts, which enable the manipulation and mastery of the environment for human benefit, there are also adverse effects. Humans are the first living beings to recognise some profound and disturbing realizations: that they exist; that there is something called the future; that all future events are uncertain except death, which is the only certainty of life. Such realisations, especially the awareness of mortality, can be frightening. Combined with our propensity to misapply the teleological module (note that all these are the result of STA), it is easy to appreciate the our tendency to draw conclusions such as the following: the Universe must be created by immanent god(s); there must be a purpose to life; part of self will live even after death; suffering endured in the present life must be due to sins of a past life; sinners will be punished in an after-life; disasters, disease and death are due to wrath of a god(s) and can be appeased by rituals; it is possible to predict life events by the position of planets and stars at birth; or, a failure in an endeavour is due to someone else casting an envious evil-eye. Thus, human religious beliefs, rituals, astrology and other superstitions can be explained by the appearance of STA.

Recall that some the earliest archaeological evidence of modern human behaviour that appeared about 40 – 50,000 years ago is burial of the dead and rituals. Such behavioural traits can be explained by the cognitive traits of existence-awareness, mortality-awareness and the notion of causation, which I claim are due to STA.

4.9. Music

Consider music. All forms of music, be it melody, harmony and polyphony are based on the denominator of time. A musical piece takes a form and appeals to our aesthetic sense only because it has a combination of notes in a precise sequence. Rhythm, another essential component of music, is nothing but a form of time.

Another intriguing idea concerns musical notes itself: is our ability to identify sounds of specific frequencies as musical notes a direct consequence of the manner in which our brains are hard-wired to appreciate time? (please note that frequency itself is a function of time!) Perhaps signals in the higher auditory neural network that represent frequencies of specific musical notes ‘resonate’ with the intrinsic activity of the neurons responsible for STA to produce the sensation of music? Thus music cognition may be a by-product of the way our brain is wired for time cognition!

4.10. Intentional Stance and ‘Theory of Mind’

One notable but inevitable by-product of self-awareness (which, I have proposed, is the result of STA) is our innate ability to infer the existence of self-awareness in other human beings too, if not in all living and non-living things. The moment we became aware that we are thinking and imagining beings, we have also become aware that other humans beings too are thinking and imagining beings; in other words, we are able to impute that our fellow human beings too have intentions like ourselves. This so called intentional stance, (a term coined by philosopher Daniel Dennett) is a uniquely human trait. For example, almost all women are exquisitely sensitive to lustful intentions of men and can instinctively pick up subtle signals about such intentions from men’s expression and body language. In fact, we have a tendency to assign intention or purpose to everything, both living and non-living. This must be the reason why we tend to infer cause and effect to random and unrelated events, which predisposes us to believe in astrology and superstitions. This must be the reason why we humans expect life to have a purpose! This must be the reason that we tend to believe in God!

Closely related to intentional stance is the so called “theory of mind”. This refers our unique ability to infer that other human beings also have a mind such as ours. Thus we are able to guess what other human beings think and hence predict their actions. Most of our social interactions are based on our ability to guess the cognitive processes of our fellow human beings. As outlined above, we have a tendency to misuse cognitive traits outside the limits for which they were specifically evolved. One such tendency is to presume that other living beings (not to mention non-living things) too have thoughts and intention like us; we tend to misuse the theory of mind on animals. In other words, we tend to think that animals, especially pets, have a mind such as ours. Thus, based on their behaviour, we impute thoughts in animals such as dogs when in reality none exist. It is has been clearly shown in scientifically conducted experiments that no animal is shown to possess a theory of mind such as us; every animal tested so far has conclusively failed the basic tests for existence of mind. Dog lovers, I am sorry! Dogs definitely do not think the way we think they think. The illusion arises because we use theory of mind out of context. Such misuse also is the reason why don’t find it one bit odd when animals talk and behave like humans in cartoons and animation movies. This phenomenon called anthropomorphism, is most pronounced in childhood. The fact that even infants don’t find anthropomorphism odd is proof enough that we are genetically programmed and hard-wired for intentional stance; perhaps, it is more surprising that even as adults, when we are cognizant that thinking, imagining and talking are exclusive human traits and that animals can’t think and talk like we do, we don’t find anthropomorphism odd at all. Even as adults we enjoy excellent animation movies! Let me reiterate again – intentional stance and theory of mind are unique human abilities, being products of existence-awareness and STA. It can explain a lot of uniqueness of human behaviour, both rational and irrational.

4.11. Arts

Our ability to create and appreciate works of art is due to STA? May be I am pushing the boundaries here, but there is some link between art and STA. Though creation and appreciation of art involves the unique ability to imagine symbols and objects (due to sophisticated space-awareness), art may have evolved as an evolutionary defence mechanism designed to distract humans from fear about the inexorable passage of time and ultimate death. Creation of a work of art may represent an attempt to freeze time or a means to defeat death and achieve immortality. Contemplation of a work of art is likely a method used to ignore, albeit temporarily, the sense of self and time. These ideas can be generalised further to argue that the human sense of aesthetics developed as a survival tool to counteract the adverse effects of STA.

4.12. Humour

The link between STA and humour is also tenuous. Humour invariably has a narrative that culminates in an unexpected and harmless twist. Narrative or story-telling, built-up anticipation, deflation of expectation and inconsequential new interpretation are due to STA. It is also well known that the most important determinant of good humour is timing. Dr. Ramachandran, in his book, The Tell-Tale Brain, has mentioned that humour is thought to have evolved as a mechanism for managing the struggle against the ever-present fear of death. As noted in Section 4.8, fear of death is a result of STA and sophisticated existence-awareness.

Thus, STA appears to be the cognitive trait that unites the three major areas of human endeavour, namely science, religion and the arts. The ideas discussed thus far are schematically presented in Fig. 2.

Figure 2. A provisional schema depicting how time-awareness affects other human cognitive and behavioral traits. Although traits are shown separately for simplicity, it should be noted that there is considerable interaction between them. For example, language has a specific set of logical rules in the form of syntax; the nature of self and that of existence, borne out by existence-awareness, are profound questions of philosophy; the teleological principle of cause and effect is central to the scientific method (this notion has been challenged by recent advances in science, most notably by inquiry into the ultimate nature of space and time).a: The hypothesis that time-awareness could have evolved as a by-product of mental rules for multi-part tool-making ability and/or language is indicated by a dashed arrow with a ‘?’ mark beside it.

5. Evolution of STA

“Okay, granted,” you might say, “STA may be the mental trait that makes us human. But, how do you think STA itself evolved?” Well, I don’t know and we can only speculate.

All biological processes are a function of time. This includes the simple stimulus-response behaviour of a unicellular organism. As life evolved, some cells in the multi-cellular organisms specialized as carriers of information resulting in the development of nervous system. Further specialisation of nervous system resulted in the appearance of a central nervous system with a brain. A sophisticated brain enabled higher animals to form mental images which helped them to mount an even more sophisticated response to a stimulus. It must be noted that even such sophisticated responses are also anchored by time. But no amount of such sophisticated behaviour implies that the organism is aware of time.

As life evolved further, it is plausible that there was a meta-representation of time from the lower brain centres to the evolving cerebral cortex of some mammals, possibly leading to a proto-time-awareness. This proto-time-awareness likely represents the information of time present in all biological processes in the body and in the external world events arriving as sensory data. After a few further million years of gradual evolution, it is possible that proto-time-awareness in hominids underwent a radical sophistication about 200,000 years ago, leading to a full-blown sophistication of time-awareness, which includes all of Pöppel’s elementary time experiences.

The underlying mechanism that led to the sophistication of proto-time-awareness into STA is unknown. Though it may have happened de novo, it is also possible that such sophistication can happen secondary to sophistication of other cognitive traits; there are a few such possible candidates.

One candidate is our hominid ancestors’ attempts to create more sophisticated tools; such attempts could have resulted in mental rules for the creation of multi-part tools. It is not difficult to envisage the natural selection of such rules because of the enormous survival advantage they confer. Mental rules for creation of multi-part tools surely must involve the ability to sequence or rearrange the steps involved in such rules. There could have been a ‘positive, recursive feedback loop’ between multi-part tool-making and its mental rule. Time-awareness could have been a by-product of such mental rules. It is well-known that, in complex systems, such positive, recursive feedback loops can lead to emergence of completely new phenomena.

Another possible candidate that led to STA is communication. As hominid hunting techniques became more sophisticated involving larger and more dangerous animals, it was imperative for individuals to co-operate. Such co-operation likely entailed sophistication of communication. At first, such communication was probably done by simple hand gestures and/or simple sounds and grunts. Natural selection would have favoured sophistication of communication because of the survival advantage conferred by it. Sophisticated communication must involve the ability to sequence gestures or sounds to convey complex information. As in the case of sophisticated tool-making, there could have been a positive, recursive feedback loop between sophistication of communication and its mental rule, and STA could have been a by-product of such a process.

It is interesting to note that such feedback loops for tool-making and communication could have co-existed and co-evolved because the selection pressure posed by the environment was the same, namely the need to hunt larger, more nutritious but more dangerous animals. Thus, there likely must have been ‘cross-talking reinforcement’ of these feedback loops which could have accelerated the appearance of STA. Such a hypothesis correlates well with the finding that the skulls of anatomically modern humans about 200,000 ago, such as the Cro-Magnons, show a rapid expansion of the Broca’s area, the brain region predominantly involved in tool-making! The finding that tool-making and language centres are in close proximity in the Broca’s area of human brain also lends further credence to this hypothesis. STA, once established, can, in turn, lead to further sophistication of tool-making and language (as shown in Fig. 2).

Other possible mechanisms include hominid attempts to master fire, or geographical, social-demographic and climatic factors. Again, such mechanisms could have acted synergistically to produce STA.

5. STA and Human Behavioural Modernity

Whatever the mechanism of evolution of STA, I hypothesise that it is the cause for the appearance of modern human behaviour about 40 – 50,000 years ago. Through millions of years of adaptive evolution, the human nervous system became aware of time about 200,000 years ago, the fundamental but mysterious phenomenon of reality that underpins all life, including all biological processes. Such a mental awareness of time also proved to be useful for other evolving cognitive processes. What likely followed is an example of the evolutionary mechanism of exaptation, in which awareness of time was applied to other pre-existing (and co-evolving) cognitive traits such as proto-self and memory resulting in an increase in sophistication and a radical and abrupt change in the behaviour of Homo sapiens in Africa. In other words, once sophisticated mental awareness of time arose by whatever mechanism, the entire neocortex with its cognitive modules was synchronised to it – the human brain literally became a time-aware machine! This mechanism of exaptation could have occurred over a relatively short period of approximately 150,000 years, from ~200,000 years ago to the appearance of modern human behaviour in Africa 40 – 50,000 years.

4. Summary and Conclusions

Sophisticated awareness of time is the cognitive trait that makes humans unique. STA likely appeared as a by-product of mental rules that evolved for multi-part tool-making or communication approximately 200 ky ago. Exaptation of this STA to other cognitive traits caused an evolutionary phase transition that happened 50-40 ky ago. Thus, STA led to the exponential development of thought, language, religion, philosophy, mathematics, music, arts, science and technology. It is the trait that led to cultural explosion and ultimately to human civilisation. In short, humans became behaviourally modern upon becoming aware that the ‘clock is ticking’ and of such simple but profound concepts of time, such as ‘before’, ‘after’ and ‘simultaneous’. It is probably more appropriate to call behaviourally modern humans Homo horo sapiens.

The STA hypothesis can thus provide answers to the 2 important questions that were raised in Section 1.